the crop or dilatation of the cesophagus of granivorous birds, in which the food is accumulated and macerated, but not digested.

Inguina Lat.), in anatomy, belonging to the groin; as, Inguinal hernia, hernia of the groin;-Inguinal glands, glands situated in the groin;-Inguino-cutaneus, the anterior branch of the first lumbar nerve.

Inhab'itiveness, in phrenology, the organ which gives the love of particular regions or countries, or, in other words, the love of home. It is also termed concentrativeness.

Inhaler, in pathology, a contrivance for breathing or drawing warm steam into the lungs, as a remedy for conghs and catarrhal complaints. In'in Gr. is, inis a sinew), in anatomy, the ridge of the occiput.

Ink Durch inkt, a fluid, or semi-substance, of various colours, used for writing or printing. The processes for making inks are various, some of which are of a purely scientific mature. According to Brande, the ordinary black writing ink consists of the tannogallate of iron, suspended in water by gum arabic-the colour being deepened and improved by the addition of a little logwood - Blue iné is produced from sulphate of indigo-Red ink is a solution or alum coloured with Brazil wood.Marking or indelible ink is a soktion of nitrate of silver. Sympathetic inks are compounds which, wihem written with, remain invisible

beated, as solutions of cobalt, c. Printing ink is made from boged linseed or nut oil, burned and mixed with lamp-black and soap. For coloured inks various pigments are used, as red-lead, vermilion, &c. -Ink stones are a sort of small round stones, of white, red, grey, yellow, or black colour, containing a quantity of native martial vitriol, from which they derive the property of making ink, and hence their name. They are almost entirely soluble in water.

Inoculation (Lat.), in anatomy, the practice of communicating a disease, especially the small-pox, by inserting contagious matter. The insertion of the virus of the cow-pox is called vaccination. -In horticulture, inoculation is the act or practice of inserting buds of one plant upon the stock of another.-In agriculture, the inoculation of grass lands is the turn

ing a ploughed field into a meadow. Inosculation (Lat.), in anatomy, union by junction of the extremities, as in arteries or veins.

Insaliva'tion (Lat.), in physiology, the admixture of saliva with the aliment during the act of mastication.

Insconced (Fr.), in military science, a term used when any part of an army has fortified itself with a sconce, or small work, in order to defend some pass.

Insect (Lat. in, and seco to cut), a numerous class of invertebrate animals, whose bodies are composed of three distinct parts joined together, with three pairs of feet, and generally wings.

Insertion (Lat.), in pathology, the same as inoculation. - In anatomy and botany, the intimate attachment of one part or organ to another, as the insertion of a ligament, muscle, or its tendon into a bone; or, in botany, that of a corolla, stamen, pistil, leaf, or ovary into any determinate point of a plant.

Insessores (Lat. perchers), in ornithology, an order of birds which habitually perch on trees. Insist (Fr. insister), in geometry, an angle is said to insist upon the arc of the circle intercepted between the two lines which contain the angle. In Situ (Lat.), in mineralogy, a term frequently applied to minerals when found in their original bed or stratum. Instinct (Lat. instinguo to urge on), in physics, the power by which animats are directed unerringly to do whatever is necessary for their preservation and the continuance of their species. In'sulator (Lat.), in electricity, a nonconductor, by which the electric current is insulated.

(Ital. intagliare to carve), in sculpture and gem-engraving, a stone in which the subject is hollowed out, so that an impression from it would present the appearance of a bas-relief. In'teger (Lat. entire), in arithmetic, a whole number, as distinct from a fraction. - Integral calculus, in mathematics, is the reverse of the differential calculus, and corresponds with the inverse method of fluxions. Integuma'tion (Lat. intego to cover), in

physiology, that which treats of the integuments of animals or plants.

Inter, a Latin preposition signifying between or among, and used as a prefix to numerous words connected with anatomy and physiology; as, Interauricular, applied to the septum between the auricles of the heart in the fœtus;-Intercervical, situated between the cervical vertebræ;-Interclavular ligament, a ligament which, passing transversely across the sternum, connects the heads of the two clavicles;-Intercostal, applied to certain muscles, blood-vessels; arteries, and nerves, which are situated or distributed Letween the ribs ;-Intercurrent, applied to fevers or other diseases which occur sporadically in the midst of an epidemic; - Interlateri costal, applied to the external intercostal muscles;-Interlobular, applied to the great fissure which separates the anterior from the middle lobe of the brain;-Intermaxillary bone, an osseous piece which exists between the superior maxillary bones of certain adult mammifera, and also of those of the human fœtus, and receives the superior incisor teeth; -Interosseous, applied to various parts and organs situated between the bones;-Interparietal bone, a cranial bone situated, in the mammifera, between the parietal frontal and superior occipital bones;-Interpleuri-costal, applied to the internal costal muscles;-Interscapular, applied to the region situated between the scapulæ;-Interspinales cervicis, six small muscles situated between the spinous processes of the neck ;Intervertebral, situated between the bodies of the vertebræ, as the invertebral ligaments, or fibro-cartilages. -Craig.

Interax'is (Lat.), in architecture, the space between the axis in columnar erections. "Doors, windows, niches, and the like, are placed centrally in the interaxis."-Gwilt.

Intercolumnia'tion (Lat.), in architecture, the distance between two columns measured at the lower part of their shafts.

Intercos'tal (Lat.), in anatomy, applied to the muscles, arteries, veins, and nerves situated between the ribs. Interganglion'ic (Lat. and Gr.), in anatomy, lying or extending between ganglions.

Interior (Lat.). In geometry, Interior angle is an angle formed within any figure by two straight-lined parts of the perimeter or boundary of the figure. The term is also applied to the two

angles formed by two parallel lines, when cut on each side of the intersecting line.

Intermittent (Lat.), in pathology, an epithet applied to a fever or other disease, the paroxysms of which recur at fixed or uncertain periods; also, to a pulse which, after some vibration, is observed to stop for a short time.

Intermodil'lion (Lat.), in architecture, the space between two modillions.Interpilaster is the interval between two pilasters.

Interneural (Lat. inter, and Gr. neuron nerve),) lying between neural processes in vertebræ.

Interscen'dant (Lat.), in algebra, interscendant quantities are when the exponents of their powers are irrational.

Intersection (Lat.), in mathematics, the cutting of one line or plane by another.

Inter-tie, in architecture, a horizontal piece of timber framed between two posts to keep them together. Intertrigo (Lat.), in pathology, a species of erythema, superinduced by acidity of the fæcal or urinary evacuations.

In'tervale, in geology, an alluvial deposit on the bank of a river.

Intestinalia (Lat.), in zoology, a class of animals which infest the interior

of other animal bodies.

Intestines (Lat.), in anatomy, a convoluted muscular canal, contained in the abdominal cavity, and extending from the stomach to the anus. They are distinguished into two portions, the small and the large; the former divided into duodenum, jejunum, and ilium; and the latter into cæcum, colon, and rectum.

Intona'tion (Lat.), in speaking, reading, or singing, the modulation of the human voice. In music, the action of sounding the notes of the scale with the voice or an instrument, compared with another voice or instrument.

Intor'sion (Lat.), in botany, the bending of any portion of a plant towards one side or the other.

Intra'dos (Ital.), in architecture, the interior and lower line or curve of an arch in contradistinction to the extrados, or upper curve.

Intra-u'terine (Lat. inter, and uterus the womb), within the uterus or womb.

Introrse (Lat.), in botany, applied to anthers which open on the side next the pistil.

Introsuscep'tion, or Intussusception (Lat. intus within, and suscipere to

receive), in anatomy, the act whereby substances about to undergo the process of assimilation are introduced into the interior of organized bodies, to be absorbed for the purposes of nutrition.

In'uline, a peculiar vegetable substance extracted from elecampane.

Inverse (Lat. inverted), in arithmetic and algebra, Inverse proportion is the rule of three, or proportion, applied in a reverse or contrary order. -Inverse ratio is the ratio of the reciprocals of two numbers.-Inverse method of tangents is the method of finding the curve belonging to a given tangent, as opposed to the direct method. -Inversion, in mathematics, is the inverting of the terms of a proportion by changing the antecedents into consequents, and the consequents into antecedents.-In music, the change of position either of a chord or a subject. In pathology, Inversio uteri is that state of the uterus in which it is turned inside out.

Invertebra'ta (Lat. invertebrates), in zoology, an important division of the animal kingdom, including all those animals which are not possessed of a vertebra, or backbone.

Involucel (Lat. dimin. of involucrum), in botany, a partial involucrum. Involucrum (Lat. a wrapper), in botany, a term applied to the bracteas which surround the flowers of umbelliferous plants.

Involution (Lat.), in arithmetic and mathematics, the raising of quantities from their roots to any powers assigned.

I'odal (Gr.), an oleaginous liquid. l'odate (Gr. iodes violet colour), a salt composed of iodine, oxygen, and a base.

Iod'ic, l'odous (Gr.), noting an acid containing iodine and oxygen.

l'odide (Gr.), a compound of iodine and

a metal.

Iodine (Gr.), a substance of a bluishblack colour and metallic lustre. It is one of the elementary bodies obtained from certain marine plants. It is incombustible, but, in combination with several other bodies, it exhibits the phenomena of combustion. Like chloride, it destroys vegetable colours.

I'odism (Gr.), in medicine, a morbid condition sometimes produced by the use of iodine.

Iod'uret (Gr.), a combustible compound substance containing iodine. I'olite (Gr. iodes, and lithos a stone), a mineral of a violet colour, which occurs massive and crystallized in

six-sided prisms. Its constituents are silica, alumina, magnesia, oxide of iron, and manganese: sp. gr. 2.56; Η-70-7.5.

Ion'ic, relating to one of the five orders of architecture, whose distinguishing feature is the volute of the capital. Ions, the elements into which a body is separated when subjected to electro-chemical decomposition.

Ipecacuan'ha, in materia medica, the root of the plant Cephaelis ipecacuanha, imported from Brazil, and used as a powerful emetic. There are several varieties.

Ire'ne (Gr.), in astronomy, the name of one of the newly-discovered planets, first observed by Hind in 1851. Its mean distance from the sun is 246,540,000 miles, and the time of its periodical revolution is 4 years and 57 days.

Irida'ceæ, Irid eæ (Gr. iris the rainbow), in botany, a nat. order of narcissal Endogens, consisting of herbaceous plants, of which the Iris, or Fleurde-lis, is the type.

Iridium (Gr. iris), in mineralogy, a whitish-coloured metal found in the ore of platinum: sp. gr. 18.-Iridosmine is a natural alloy of iridium and osmium, consisting of iridium, osmium, and iron: sp. gr. 18-25-19.5; H. = 4.5.

Iris (Gr. the rainbow), in anatomy, the ring-shaped diaphragm which surrounds the pupil of the eye, so called from being coloured.-Iris, in astronomy, one of the newly-discovered planets, first observed by Hind in 1847; its mean distance from the sun being 227,550,000 miles, and the time of its periodical revolution 3 years and 250 days.

Irish Moss, in botany, the name of a marine plant brought from Ireland, obtained from the Chondrus crispus. Being of an emollient and demulcent property, it is used medicinally, and for various economic purposes. Iri'tis (Gr. iris), in surgery, inflammation of the iris of the eye. Iron (Sax. iren), the most general and useful of the metals, extremely hard, yet fusible and malleable. It is exceedingly ductile, and distinguished from every other metal by its magnetic properties: sp. gr. 7.6-7.8. All acids act upon iron, and nitric acid oxidizes it with great vehemence. It is capable of combining with a number of metals, but it does not unite with lead or bismuth, and very feebly with mercury.

Iron forms a prefix to a variety of terms connected with science and the arts; as, Iron-flint, a variety of

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